15 min fix for jam free QU-BD

Re: 15 min fix for jam free QU-BD

oops. I read "Now do the same with the short piece" and thats what I did LOL.

Re: 15 min fix for jam free QU-BD

Posted: Sat Apr 06, 2013 8:13 pm

by REdington

OK I went back and edited it.

Re: 15 min fix for jam free QU-BD

Posted: Tue Apr 09, 2013 5:36 pm

by bloomingtonmike

My ABS print after doing this mod!

Re: 15 min fix for jam free QU-BD

Posted: Thu Apr 11, 2013 4:19 pm

by keos

Guys enclosed is an image i created with a thought and a questionRodney can you see this and let me know if this will work.....

Keos

Re: 15 min fix for jam free QU-BD

Posted: Thu Apr 11, 2013 5:44 pm

by REdington

Keos I haven't tried one that short. I made some of my own barrels out of 303 stainless rod on the lathe that were longer. Yes, I think it should work as long as you have a square shoulder in barrel for the PTFE to go against. One of the first ones that I made, I just drilled the barrel as in your diagram and the bevel left by the bit caused the PTFE to compress on the filament from the pressure at the nozzle pushing up on the tube. I was going to use a endmill and do it the way you have it drawn up, but 99% of the people don't have endmills laying around. Another thing is that you will have to find a skinny wrench or grind one down to fit between the coldend and hotend to tighten the jam nut.

If you try one that short, let us know how well it works.

Rodney

Re: 15 min fix for jam free QU-BD

Posted: Thu Apr 11, 2013 7:34 pm

by keos

REdington

bevel left by the bit caused the PTFE to compress on the filament from the pressure at the nozzle pushing up on the tube

what about if you have two drill bit that are the same , take one of them and chop down or grind off the tip of the drill bit to make it flat more or less like a mill bit, would that remove the bevel that was created by the first drill bit , do you think this will work....

keos

Re: 15 min fix for jam free QU-BD

Posted: Thu Apr 11, 2013 8:58 pm

by REdington

I think that will work.

Rodney

Re: 15 min fix for jam free QU-BD

Posted: Sun Apr 14, 2013 5:44 am

by bloomingtonmike

REdington wrote:Keos

Another thing is that you will have to find a skinny wrench or grind one down to fit between the coldend and hotend to tighten the jam nut.

If you try one that short, let us know how well it works.

Rodney

A solution to the small wrench and smaller barrel is assemble it in reverse from QUBD instruction - change order of build.

Put the short piece in leaving enough room for the top not (I like to use it for guiding the filament ) and the room to tighten it against the long tube. Take nut off. Insert long barrel from bottom. Tighten short barrel against long barrel. Put on top nut and tighten. Install cold end on motor and heat sink/fan. Install extruder on mount and use nut on bottom of long barrel and tighten to mount. Then install hot end on barrel (with nozzle 1/2 turn loose from tight) and screw hot end to nozzle. Now tighten nozzle. Now install thermistor and fiberglass wrap.

Re: 15 min fix for jam free QU-BD

Re: 15 min fix for jam free QU-BD

Posted: Mon Apr 15, 2013 2:10 pm

by codepunk

I have been waging a ongoing war with my qu-bd since I installed it. I have tried a whole bunch of things that did not work, and a couple that did.

1. MK7 minimum with stock drive gear, total bust2. QU-BD block with set screw modified with metal slug, o rings for compression and set screw, a little better but not much3. Modified the stock drive gear by running a demel cutting wheel between all the gear teeth, wow huge improvement with the modified qu-bd setup but still jams occasionally but I have pulled off 3 hr prints. Hardto find a MK7 gear at the moment but running the dremel between the teeth made a huge difference in the grip.

Now I run across this thread and I am going to try two versions of this mod which I am betting will finally give me a rock solid trouble free extruder.

I ordered a new drive gear from trinity labs even though my dremel mod is pretty darn good, I also ordered the PTFE and in addition I ordered a chunk of PEEK rod. My plan is to try this mod of the stainlessbarrel and also try replacing the stainless barrel with one made of threaded PEEK and the PTFE liner down the center. Modifying the stainless barrel I have little doubt will cure all of my issues but I cannot helpbut to think making new barrel out of PEEK lined with PTFE would be the ultimate fix.